The present invention relates to automatic clothes washing machines and more particularly to an improved structure in such machines for effecting the washing of relatively small loads of clothing and especially heavily soiled clothing in a high detergent concentration.
Automatic clothes washing machines customarily provide, in a clothes basket adapted to hold several pounds of clothes, a sequence of operations in order to wash, rinse and extract water from the clothes in the basket. The sequence ordinarily includes a water fill followed by a washing operation which, in a vertical axis type machine, is provided by an agitator movably arranged to oscillate within the basket; a first centrifugal extraction operation in which the wash water is removed from the clothes by spinning the basket; another water fill followed by a rinsing operation in which the clothes are rinsed in clean water while the agitator is oscillated; and a final centrifugal liquid extraction operation in which the basket is spun to remove rinse water from the clothes. Machines having this type of cycle, or a variation thereof, generally produce highly satisfactory results in that the clothes come out properly cleaned and with a substantial part of the liquid removed.
In the case where clothes are extremely dirty or soiled with difficult to remove spots, they will emerge from the cycle of operations with at least some of those spots still visible. Generally, these exceptionally dirty clothes are a minority relative to a full wash. Thus, it would not be economical to add extra detergent to the full load of clothes just for the sake of cleaning an isolated heavily soiled item.
These types of clothes should be washed by themselves so that special treatment may be given to each item. One disadvantage which presents itself when very small loads are washed in the basket of a washing machine is that the amount of water required for washing a few items may be comparable to the amount of water used for washing several pounds of clothing. This, of course, represents an inefficient use of water with a resulting high cost of water and energy in heating the water in consideration of the results being obtained. Also, there is a correlary that the greater the quantity of water used, the greater the quantity of detergent needed in order to effect a proper detergent concentration in the water. This is even more critical in the instance of heavily soiled clothes which would require greater amounts of detergent. Considerations such as these have quite often led the owners of domestic clothes washing machines to do the washing of heavily soiled clothes by hand despite the availability of the machine.
One solution to this problem is the use of a small basket placed on the agitator inside the larger regular wash clothes basket. The motion of the agitator carries with it the small basket and provides a motion of the liquid in the basket which causes a suitable type washing action. This type of washing machine is described in U.S. Pat. No. 3,014,358 and is assigned to the assignee of the present invention. In the use of a small wash basket as described in U.S. Pat. No. 3,014,358 the clothes within the small basket are subjected to the same operational cycles as when the machine is used with a "normal" operation. The disadvantage in such a clothes washing cycle is that the water is continuously recirculated through the small basket. Accordingly, while the smaller basket has a relatively small volume the water level in the smaller basket is maintained by circulating all of the water in the machine machine through the smaller basket during the washing operation. This causes the detergent that is placed in the small basket to be diluted into the recirculating water in the machine.
By the present invention means are provided whereby during the washing cycle of operation only a predetermined volume of the fill water is circulated into the smaller basket during a timed recirculation cycle prior to the wash cycle. This relatively small volume of water is retained therein during the entire washing cycle of operation. This ability to confine a limited water volume allows for the attainment of a very high detergent concentration with the usage of reasonable and acceptable amount of detergent. Following this initial wash in a high detergent concentration the machine reverts to its "normal" cycle of operation; wherein all of the fill water in the machine is recirculated through the small basket during the ensuing spin, rinse, and extraction cycles of operation.